If you find that it's too tricky to complete the whole ladder in 20 minutes, you can bypass a column (if you have already completed it on your first go) by typing 'COLUMN 1', 'COLUMN 2' or 'COLUMN 3'. For example, after you complete column 1 (or 1 & 2), you can restart the quiz, type in "Column 1" (or "Column 1" and "Column 2"), and get credit.